html,
body {
  height: 100%;
}

body {
  font-family: sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0;
}
body * {
  margin: 10px;
}

.pagination {
  filter: drop-shadow(0 5px 15px rgba(0, 0, 0, 0.3));
}
.pagination__item {
  font-weight: bold;
  background-color: transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 30px;
  height: 30px;
  width: 30px;
  margin: 5px;
  padding: 0;
  -webkit-user-select: none;
     -moz-user-select: none;
          user-select: none;
}
.pagination__item--button {
  position: relative;
  border: none;
  outline: none;
  cursor: pointer;
}
.pagination__item--button, .pagination__item--button::before {
  transition: all 0.3s ease;
}
.pagination__item--button::before {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: #333;
  transform: scaleX(0);
}
.pagination__item--button:hover::before {
  transform: scaleX(1);
}
.pagination__item--button.active {
  background-color: #333;
  color: #eee;
  box-shadow: 2px 2px 0 0 #0ff, -2px -2px 0 0 #f00;
}
.pagination__item--button.active:hover {
  box-shadow: -2px -2px 0 0 #0ff, 2px 2px 0 0 #f00;
}